Vertically and horizontally polarized omnidirectional antennas and related methods
An omni-directional antenna module includes a plurality of vertically and horizontally polarized antenna elements arranged to provide 360° coverage around an antenna, and to eliminate nulls below the antenna. The antenna elements are arranged in parallel with respective orthogonal axes of a three-dimensional Cartesian coordinate system, with the centers of the antenna elements being arranged collinearly along the vertical or “Z” axis so that the radiation patterns of the individual orthogonally polarized dipoles do not interfere.
1. An omnidirectional antenna module consisting of:
a set of three vertically polarized antenna elements disposed in a collinear arrangement along a vertical Z-axis of a three-dimensional Cartesian coordinate system; and
a set of five horizontally polarized antenna elements arranged such that a center of each horizontally polarized antenna element is positioned along the Z-axis with the set of three vertically polarized antenna elements, wherein
a first horizontally polarized antenna element of the set of five horizontally polarized antenna elements extends in a horizontal X-axis direction of the three-dimensional Cartesian coordinate system and is arranged concentrically a first vertically polarized antenna element the set of three vertically polarized antenna elements, forming a first pair of orthogonal antenna elements,
a second horizontally polarized antenna element of the set of five horizontally polarized antenna elements extends in the horizontal X-axis direction and is arranged concentrically a second vertically polarized antenna element the set of three vertically polarized antenna elements, forming a second pair of orthogonal antenna elements,
a third horizontally polarized antenna element of the set of five horizontally polarized antenna elements extends in the horizontal X-axis direction and is arranged concentrically a third vertically polarized antenna element the set of three vertically polarized antenna elements, forming a third pair of orthogonal antenna elements,
a fourth horizontally polarized antenna element of the set of five horizontally polarized antenna elements extends in a horizontal Y-axis direction of the three-dimensional Cartesian coordinate system and is situated between the first pair and the second pair of orthogonal antenna elements, and
a fifth horizontally polarized antenna element of the set of five horizontally polarized antenna elements extends in the horizontal Y-axis direction and is situated between the second pair and the third pair of orthogonal antenna elements.
2. The omnidirectional antenna module as claimed in claim 1 , wherein the set of three vertically polarized antenna elements are arranged to exhibit a one-wavelength spacing between adjacent vertically polarized antenna elements.
3. The omnidirectional antenna module as claimed in claim 2 , wherein the fourth and fifth horizontally polarized antenna elements are arranged to exhibit a one-half-wavelength spacing between adjacent pairs of orthogonal antenna elements.
4. The omnidirectional antenna module as claimed in claim 1 , wherein the set of three vertically polarized antenna elements and the set of five horizontally polarized antenna elements comprise dipole antenna elements.
5. The omnidirectional antenna module as claimed in claim 1 , wherein the set of three vertically polarized antenna elements and the set of five horizontally polarized antenna elements comprise slot antenna elements.
6. A method for configuring an omnidirectional antenna comprising:
arranging a set of three vertically polarized linear dipole antenna elements in a collinear configuration along a vertical Z-axis of a three-dimensional Cartesian coordinate system;
arranging a set of three horizontally polarized linear dipole antenna elements concentrically with the set of three vertically polarized linear dipole antenna elements, with a center of each horizontally polarized linear dipole antenna element positioned on the Z-axis, the set of three horizontally polarized linear dipole antenna elements oriented parallel to a X-axis horizontal direction of the three-dimensional Cartesian coordinate system;
positioning a fourth horizontally polarized linear dipole antenna element between a first horizontally polarized linear dipole antenna element and a second horizontally polarized linear dipole antenna element of the set of three horizontally polarized linear dipole antenna elements, the fourth horizontally polarized linear dipole antenna element having a center positioned on the Z-axis and oriented parallel to a Y-axis horizontal direction of the three-dimensional Cartesian coordinate system; and
positioning a fifth horizontally polarized linear dipole antenna element between the second horizontally polarized linear dipole antenna element and a third horizontally polarized linear dipole antenna element of the set of three horizontally polarized linear dipole antenna elements, the fifth horizontally polarized linear dipole antenna element having a center positioned on the Z-axis and oriented parallel to the Y-axis horizontal direction.
7. The method as claimed in claim 6 wherein the set of three vertically polarized linear dipole antenna elements is arranged to include a one-wavelength spacing between adjacent linear dipole antenna elements, and the fourth and fifth horizontally polarized linear dipole antenna elements are positioned at a one-half-wavelength location between adjacent horizontally polarized linear dipole antenna elements.
8. The method as claimed in claim 6 further comprising the step of
mounting the omnidirectional antenna module in a single radome of a small cell base station.